The invention consists of a fixation device used to immobilize portions of a fractured bone relative to one another, and more specifically to a device to immobilize such portions of fractured bone by attaching an adjustable rigid frame to the fractured bone.
A fixation device is known from DE 41 13 083 A1. This fixation device has three or four rings used as clamping jaws, said rings being designed as either closed or sector rings. The rings are connected with one another by rods. For mutual positioning of the rings, the rods are axially displaceable and pivotable with respect to the rings and can be clamped in position respective to the rings. Holders are provided on the rings for bone wires or bone fixation and retaining pins.
The known fixation device permits free relative movement of the rings in space, so that the bone fragments can be positioned and repositioned very exactly. The fixation device is secured in a stable fashion in precisely set positions by clamping the rods to the rings.
A fixation device is also known from DE 94 01 291 U, that has only two clamping jaws for provisional emergency care of the patient, with each sector ring having two holders for the clamping pins and with each holder having at least two receptacles for the clamping pins, i.e. the fixation and retaining pins. The receptacles are offset with respect to one another perpendicularly with respect to the plane of the sector ring. The clamping pins are designed as cylindrical pins that have a small point at their anterior ends, said point being capable of being pressed superficially into the bone. These clamping pins are provided with an external thread in their rear areas. After the clamping jaws are positioned, the clamping pins are then advanced by the suitably designed receptacle that cooperates with the external threads of the clamping pins until they rest on the surface of the bone and provide the necessary grip. This fixation of the clamping pins is cumbersome and time-consuming.
The present invention is directed to a fixation device that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the apparatus and method particularly pointed out in the written description and claims hereof, as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described, the invention is a fixation device with clamping jaws having rods connecting the clamping jaws, said rods being adjustable axially and angularly relative to the clamping jaws and being clampable in a desired position, and with fixation and retaining pins that can be received in a clampable fashion in the clamping jaws. The device has a fixation pin applicator releasably connectable with the clamping jaws, by means of which applicator a fixation pin can be brought into a desired position.
Accordingly, the clamping jaws are releasably connectable with a fixation pin applicator, by means of which applicator a fixation pin can be brought into the corresponding desired position on the surface of the bone.
The fixation device offers a minimally invasive alternative to surgery of fractures of bones such as, for example, the tibia. The individual fragments are secured in the area of the cortex in each instance without the medullary cavity being opened (so-called pinless nail method). The fixation device can be applied rapidly and simply because of the fixation pin applicator provided according to the invention, and permits intra operative and postoperative repositioning of the device and of the bone fragments in all planes.
This technique avoids contamination of the medullary cavity. A direct procedural change to using the marrow nailing method poses no risk, i.e., it can be performed without an increased risk of infection. In addition, when the fixation device according to the invention is used, the device can remain in place even during marrow nailing, if that procedure is required, considerably simplifying marrow nailing and also allowing the procedure to be performed more rapidly.
In a different embodiment, the invention is a fixation device that includes a fixation pin applicator that can be designed in the form of a pistol, and can have in addition to a fixed handle, a movable handle part by which a plunger acting on the fixation pin can be displaced.
In the fixation pin applicator, a transport plate for moving the plunger against the force of a spring can be moved by the movable handle part. The plunger and therefore the fixation pin is thus moved toward the desired position by this transport plate.
The fixation pin applicator can be secured to the clamping jaw by a latching mechanism with a catching pin in an especially simple fashion. To release the latching mechanism, the fixation pin applicator has an externally operable release that is connected to the spring loaded latching mechanism. The clamping jaw can also be held in place by a spring loaded ball affixed to the fixation pin applicator, and cooperating with a corresponding depression in the clamping jaw.
The fixation device can consist of two clamping jaws that can be maintained in the desired position with respect to one another by corresponding rods. According to one advantageous embodiment of the invention, however, additional connecting elements can be linked to the clamping jaws, said elements having suitable clamping devices to receive additional rods and hence to connect additional clamping jaws. The fixation device can thus be expanded as desired.
The fixation and retaining pins can have different shapes. In particular, the retaining pins can be made straight or bent. They can also be designed as so-called dual pins, which are forked pins located parallel to one another. The retaining pins can also be made spoon-shaped at their ends and provided with a plurality of points parallel to one another. These pins also can be in the form of single or dual pins.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.